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Coastal Navigation—Nautical Charts, Geographic Positioning, Marine Electronics, and Instruments
Published in George A. Maul, The Oceanographer's Companion, 2017
In marine navigation, speed is given in nautical miles per hour or knots (kn). The term “knot” probably came from Bartolomeu Crescêncio of Portugal, at the beginning of the sixteenth century. A line with a chip of wood attached was tossed overboard and the sailor would count the number of knots (spaced every 47.25 feet) passing through his hands in the 28 sec a sandglass would empty (47.25feet28sec×3600sechr≅6076feethr=1kn). The chip-log method gives an estimate of the ship's speed through the water, but not speed over the ground. Oceanographers often work in meters per second (m ⋅ s−1 or m/s) when measuring current speeds, but wind speeds are still mostly stated in knots. For handy reference 1 m ⋅ s−1 = 1.94 kn = 2.24 mph = 3.6 kph = 3.28 fps, where mph is statute miles (5280 feet) per hour, kph is kilometers per hour, and fps is feet per second.
Combustion characteristics of spent coffee ground mixed with crude glycerol briquette fuel
Published in Combustion Science and Technology, 2018
Sarulpop Potip, Tanakorn Wongwuttanasatian
There have been some studies related to the utilization of SCG as a fuel. Limousy et al. (2013) studied the heating values and combustion characteristics of SCG compared with pine sawdust (Picea) and SCG/pine sawdust blend pellets. Combustion tests were performed in a 8–12 kW Okofen Boiler and it was found that the combustion efficiency of the SCG pellets, pine pellets and blended pellets was 64.1%, 84.3% and 83.4%, respectively. Limousy et al. (2015) also reported a study regarding the emission gases from compressed SCG/wood chip log combustion in a residential stove. They found that the SCG promoted better combustion for the mixed SCG/wood chip log. The emissions, on the other hand, were slightly higher when the SCG portion was increased.